Question: Evaluate the following expression when $a = 7$ and $b = 9$. $4$ $a$ $ + 7$ $b$ $ - 10$
Substitute $7$ for ${a}$ and $9$ for ${b}$ $ = 4{(7)} + 7{(9)} - 10 $ $ = 28 + 63 - 10 $ $ = 81$